Injury-elicited differential transcriptional regulation of phospholipid growth factor receptors in the cornea (original) (raw)

The phospholipid growth factors (PLGFs), including lysophosphatidic acid (LPA), have been implicated in corneal wound healing. PLGF concentrations and activities are elevated after corneal injury. Using real-time PCR, we quantified receptor mRNA levels in the healing rabbit cornea. In intact corneas, transcripts for S1P1, LPA1, and LPA3receptor subtypes were detected, as was lipid phosphate phosphatase 1 (LPP1). After wounding, the trend for endothelium and keratocytes was for significant decreases in transcript numbers for the three receptor subtypes, whereas epithelial cells showed increased transcript numbers, except for an S1P1decrease in healing cells. LPP1 transcript numbers were decreased in keratocytes and endothelium, although LPP-specific activity was unchanged. LPA-elicited Ca2+transients were significantly reduced in the healing endothelium. Consistent with reduced LPA3receptor numbers, dioctylglycerol pyrophosphate, a selective antagonist, reduced LPA-induced Ca2+transi...